Classification of
food
There are many ways of classifying foods
1. Classification by origin
1) Foods of animal
origin
2) Foods of vegetable origin.
2. Classification by
chemical composition
1) Proteins
2) Fats
3) Carbohydrates
4) Vitamins
5) Minerals.
3. Classification by
predominant function
1) Body-building
foods, e.g., milk, meat, poultry, fish, eggs, pulses, groundnuts, etc.
2) Energy-giving foods, e.g.,
cereals, sugars, roots and tubers, fats and oils.
3) Protective foods, e.g.,
vegetables, fruits, milk.
4. Classification by nutritive
value
1) Cereals and
millets
2) Pulses (legumes)
3) Vegetables
4) Nuts and oilseeds
5) Fruits
6) Animal foods
7) Fats and oils
8) Sugar
9) Condiments and
spices
10) Miscellaneous
foods.
Carbohydrates
•
Carbohydrates
are the sugars and starches found in foods.
•
They
are made up of carbon, hydrogen, and oxygen.
•
Athletes
are not the only people who need carbohydrates.
•
Everyone
needs them.
•
There
are two general types of carbohydrates: simple and complex.
The Role of Carbohydrates
·
our
body converts all carbohydrates to glucose.
·
Glucose
that is not used right away is stored as glycogen.
·
When
more energy is needed, our body converts the glycogen back to glucose.
·
our
body converts and stores the excess carbohydrates as body fat.
Fats (Lipids)
•
Fats are solid at 20 deg. C; they are called
"oils" if they are liquid at that temperature.
•
Fats are the nutrients that contains the most concentrated
form of energy. Fats are type of lipid.
•
Lipids are substances that are somewhat similar to
carbohydrates, but they contain less oxygen and they do not dissolve in water.
•
Fats are part of many body tissues and are important as
carriers of other nutrients, such as vitamins.
•
Fats also carry the flavor of foods – making foods
tastier, but consumption of fat should be closely monitored.
The Role of Fats
·
They
transport vitamins A, D, and K in the blood.
·
They
serve as sources of linoleic acid—an essential fatty acid that is needed for
growth and healthy skin.
·
They
add flavor and texture to food.
·
They
satisfy hunger longer than other nutrients do.
Protein
•
Proteins are substances found in every cell. The body needs
proteins to build and repair all body tissues. Protein is an important part of
blood cells. Proteins are made up of carbon, hydrogen, oxygen, and nitrogen
atoms that are formed into basic units called amino acids.
•
There
are 20 different amino acids. Nine of them are essential, and the other eleven amino
acids can be produced by the body.
The body uses proteins to:
·
Build
new cells and tissues.
·
Replace
damaged cells by making new ones.
·
Make
enzymes, hormones, and antibodies.
·
Supply
the body with energy.
Vitamins
and Minerals
Vitamins
are essential for:
–
Building
body tissues such as bones, skin, glands, nerves, and blood.
–
Assisting
in the metabolizing of proteins, fats, and carbohydrates so you receive energy
from food.
–
Promoting
healing
–
Preventing
nutritional deficiency diseases.
Minerals
are essential for:
–
The
formation of strong bones and teeth
–
Helping
to control the nervous system
–
Fluid
balance in tissues
–
Muscle
contractions
Minerals
•
Minerals
are simple substances found in the environment that are essential to the body’s
functioning.
•
Minerals
are used to regulate a wide range of body processes, from bone formation to
blood clotting, and they are important for the body structure.
•
Most
minerals are either quickly used or lost in waste products, therefore we must
eat mineral-rich foods daily to replenish our supply.
•
Iron is an exception –it tends to be kept and
recycled by the body, except when there is a blood loss.
